Arsenal went out of a third competition in two weeks yesterday when Manchester United reached the FA Cup semifinals with a 2-0 victory that vindicated manager Alex Ferguson's selection gamble.

Seven defenders started for United and left back Fabio da Silva, playing in midfield, opened the scoring before striker Wayne Rooney headed in another in the second half.

"We got our goals, luckily I pulled off a couple of saves and we defended well," United goalkeeper Edwin van der Sar said.

The Gunners' hopes of a first title since the 2005 FA Cup now rely on overhauling United's three-point lead in the Premier League after Barcelona ended their European campaign and Birmingham beat them in the League Cup final.

Birmingham won't be returning to Wembley Stadium this season after Lee Chung-yong's 90th-minute header gave Bolton a 3-2 victory in yesterday's other quarterfinal.

Ahead of the Old Trafford match, both managers shared the same plight. Governing bodies have charged Ferguson (the FA) and Arsene Wenger (UEFA) over their conduct toward referees, while a miserable run of results left them both in need of a cup win.

But after United bounced back yesterday from Premier League losses to Chelsea and Liverpool, it is Ferguson in a buoyant mood as his focus shifts to Tuesday's last 16 Champions League match against Marseille.

With one eye on beating the French side after drawing 0-0 away, Ferguson deployed an experimental side packed with defenders that recognized the ability of Fabio and twin Rafael da Silva to play in more attacking roles on the flanks.

"I couldn't risk (Paul) Scholes and (Ryan) Giggs because of Tuesday's game," Ferguson said. "That is such an important game for the club and if you look at the injuries in midfield I had to come up with a plan or an idea to utilize our energy."

Rafael could have put United in front when his brother whipped in a cross had his header been directed lower.

But Fabio found the net in the 28th minute after starting the move with a surging run.

Having set up Rooney's cross for Javier Hernandez, whose header was palmed away by goalkeeper Manuel Almunia, Fabio sent the rebound into the net.

United's 40-year-old goalkeeper Van der Sar showed that he might be retiring too early in May by pulling off a string of fine saves from Robin van Persie and Laurent Koscielny.

Rooney extended United's lead four minutes into the second half. Hernandez's shot after latching onto Rafael's cross was blocked by Almunia, but Rooney met the loose ball with a header that lacked power but fell into the net.

Arsenal's misery was compounded when defender Johan Djourou was stretchered off after dislocating his right shoulder in a collision with teammate Bacary Sagna as Almunia stopped Hernandez scoring a third. Having used all three substitutes, Arsenal had to play with 10 men for the last 10 minutes of the match.

"I cannot fault our effort but things do not go our way at present," Wenger said. "Subconsciously I feel the disappointment of Tuesday (at Barcelona) played a part in the game. You could see something has gone, not in our effort or attitude, but confidence wise.

"But I don't feel like the season is slipping away. I believe we can do it. It is a good test for us now to show we can regroup and show the mental strength and togetherness quickly."

Bolton will be contesting its first FA Cup semifinal since 2000 when it lost to Aston Villa.

After the visitors twice threw away the lead, South Korea winger Lee ghosted into the penalty area to meet Kevin Davies' header across the goal to nod in Bolton's winner.

"Lee is capable of playing for any team," Bolton manager Owen Coyle said. "He hasn't had a break for two years though and we have to be careful with him."

Lee made an impact with his first touch after coming off the bench with 30 minutes to go, clearing the ball off the line from David Murphy following Sebastian Larsson's corner.

Bolton forward Johan Elmander's fierce left-footed strike put Bolton in front, but it was canceled out before halftime by Cameron Jerome.

Kevin Davies restored Bolton's lead with a 66th-minute penalty after being tripped by defender Curtis Davies.

Birmingham forward Kevin Phillips thought he secured a replay when he hooked the ball over goalkeeper Jussi Jaaskelainen in the 80th.

Manchester City hosts Reading and West Ham is at Stoke today.